1. Technical Field
The present invention relates generally to client-server technologies and, in particular, to techniques for enabling web sites to collect HTTP transaction performance information such as an approximate round trip time, an approximate page render time at the client, a request service time at the server, and the like.
2. Description of the Related Art
The World Wide Web is the Internet's multimedia information retrieval system. In the Web environment, client machines effect transactions to Web servers using the Hypertext Transfer Protocol (HTTP), which is a known application protocol providing users access to files e.g., text, graphics, images, sound, video, etc.) using a standard page description language known as Hypertext Markup Language (HTML). HTML provides basic document formatting and allows the developer to specify “links” to other servers and files. In the Internet paradigm, a network path to a server is identified by a so-called Uniform Resource Locator (URL) having a special syntax for defining a network connection. Use of an HTML-compatible browser (e.g., Netscape Navigator) at a client machine involves specification of a link via the URL. In response, the client makes a request to the server identified in the link and, in return, receives a document or other object formatted according to HTML. A collection of documents supported on a Web server is sometimes referred to as a Web site.
As consumer-to-business e-commerce increases on the Internet, a business will want to gather metrics that reflect its customer's experience with the Internet business services provided from the site. One such metric is the “total round trip time” for a given transaction, which represents the total time necessary to process a given HTTP transaction from the time the request is issued to the server until the page is fully rendered on the client. The total round trip time includes a number of elements: the server response time, the client page display time, and the time spent on the network.
It is known in the prior art to provide specialized software to facilitate calculation of such performance metrics. In one scheme, a user of a client machine must download and install a client-side agent that is used to calculate the total round trip time. The agent, in effect, starts a timer when the page request is issued, and the software then determines the total round trip by determining when the page has been rendered. This technique, however, is obtrusive, and it does not provide information about the server response time (except to the extent that such data is included in the total round trip time). Of course, when given the choice, most users will not install and/or use such monitoring agents.
There remains a need in the art to provide an improved technique for enabling sites to monitor HTTP transaction performance, preferably without involvement from the user of the client machine.